Dynamic service provisioning in space-division multiplexing elastic optical networks

In space-division multiplexing elastic optical networks (SDM-EONs) based on multicore fibers, the problem of finding a lightpath for a new connection request involves routing, modulation, spectrum, and core assignment (RMSCA). A lightpath can be constructed using contiguous free frequency slot (FS) blocks with different frequency slot allocation patterns (FSAPs), where each FSAP can incur different amounts of wasted FSs. Aiming at using the FSAP with the least amount of wasted FSs and exploiting path diversity, a set of new algorithms are proposed to solve the RMSCA problem. Before any connection requests arrive, all candidate paths between each pair of nodes and all FSAPs for each possible bandwidth requirement are identified and sorted. When a connection request arrives, two approaches can be used to establish a lightpath: the path-first or spectrum-first approach. We show that by packing lightpaths toward FSs with the smallest FS indexes, the spectrum-first approach leaves bigger contiguous FS blocks for future requests. As a result, the request blocking probability is minimized.